The gene for type 1 neurofibromatosis (NF1) is most highly expressed i
n brain and spinal cord, although low levels of mRNA can be found in n
early all tissues. As a first step in investigating the regulation of
NF1 gene expression, we have cloned and sequenced the promoter regions
of the human and mouse NF1 genes and mapped the transcriptional start
sites in both species. We report here that the 5' ends of the human a
nd murine NF1 genes are highly conserved. While no discernable TATA or
CCAAT box sequences are seen, transcription initiates at identical si
tes in both species, 484 nucleotides upstream of the ATG initiation co
don in the human gene. The human and mouse NF1 genes share particularl
y high sequence homology (95%) between nucleotides -33 and +261 and co
ntain several perfectly conserved transcription factor binding site mo
tifs, including a cAMP response element, several AP2 consensus binding
sites, and a serum response element. The high conservation of these s
equences indicates that they are likely to be significant in the regul
ation of NF1 gene expression. (C) 1994 Academic Press, Inc.